Satellite Echoing for Geolocation and Mitigation of Gnss Denial

2. The method as in claim 1, wherein determining the portion of the determined time difference associated with only the single traversal of the portion of the communication path that is between the communication satellite and the target device is based at least in part on removing any node-incurred delay along the communication path.

3. The method as in claim 2, wherein the node-incurred delay is a fixed time and known prior to transmitting the initiated message.

4. The method as in claim 2, wherein the node-incurred delay is indicated in the returned message.

5. The method as in claim 4, wherein the node-incurred delay is set by the communication satellite.

6. The method as in claim 2, wherein the node-incurred delay is indicated in one or more following messages received by the processing device after the returned message once the node-incurred delay is calculated by one or more nodes along the communication path.

7. The method as in claim 1, wherein determining the portion of the determined time difference associated with only the single traversal of the portion of the communication path that is between the communication satellite and the target device is based at least in part on removing portions of the communication path other than the portion of the communication path that is between the communication satellite and the target device.

8. The method as in claim 7, wherein removing portions of the communication path other than the portion of the communication path that is between the communication satellite and the target device is based on removing a known time associated with the portions of the communication path other than the portion of the communication path that is between the communication satellite and the target device.

9. The method as in claim 7, wherein removing portions of the communication path other than the portion of the communication path that is between the communication satellite and the target device is based on removing a known distance associated with the portions of the communication path other than the portion of the communication path that is between the communication satellite and the target device.

10. The method as in claim 1, wherein performing one or more actions based on the distance between the communication satellite and the target device comprises using the distance between the communication satellite and the target device for a location determination of the target device.

11. The method as in claim 10, wherein the location determination of the target device uses a plurality of distances between the target device and a respective plurality of reference objects for trilateration.

12. The method as in claim 11, wherein the plurality of reference objects for trilateration comprise additional communication satellites with respective distances to the target device being calculated based on determining a respective time difference between a respective transmission time of additional initiated messages and a respective reception time of corresponding returned messages.

13. The method as in claim 11, wherein the target device comprises a directional antenna, and wherein the target device aims separately at one or more of the plurality of reference objects.

14. The method as in claim 11, wherein the plurality of reference objects for trilateration are based on a plurality of different location determination hardware systems.

15. The method as in claim 14, wherein at least one of the plurality of different location determination hardware systems is a Global Navigation Satellite System (GNSS) and wherein at least one of the plurality of reference objects for trilateration is a GNSS satellite.

16. The method as in claim 14, wherein at least one of the plurality of distances is between the target device and a geolocated object having a known location based on a Global Navigation Satellite System (GNSS).

17. The method as in claim 11, wherein the target device comprises a directional antenna, and wherein the target device aims the directional antenna singularly at the communication satellite and communicates with one or more other communication satellites as reference objects based on adjacent satellite interference (ASI) spillover from the directional antenna for corresponding additional distances between the target device and the one or more other communication satellites.

18. The method as in claim 17, wherein the target device is the processing device, and wherein the one or more other communication satellites communicate with the communication satellite to which the target device aims as a primary communication satellite, and wherein the one or more other communication satellites are time synchronized with the target device, and wherein the one or more other communication satellites create a respective timestamp upon reception of the initiated message and communicate the respective timestamp to the primary communication satellite for return to the target device.

19. The method as in claim 11, wherein at least one of the plurality of reference objects is selected based on minimizing geometric dilution of precision (GDOP) of the location determination based on the plurality of reference objects.

20. The method as in claim 11, wherein the plurality of reference objects for trilateration includes two communication satellites and a separate altitude determination mechanism.

21. The method as in claim 1, wherein the processing device is the target device.

24. The method as in claim 23, wherein either of the known time of flight value between the satellite and the ground station or the known distance between the satellite and the ground station is known by the target device either in advance of the initiated message, or in response to the returned message.

25. The method as in claim 1, wherein the processing device is a ground station along the communication path, and wherein the target device establishes the returned message in response to the initiated message.

26. The method as in claim 25, wherein the ground station transmits the initiated message in response to a request from the target device.

27. The method as in claim 25, wherein the ground station transmits the initiated message as an unsolicited beacon to one or more target devices.

30. The method as in claim 1, wherein the processing device configures one or more adjustable transmission parameters for the initiated message.

31. The method as in claim 1, wherein the processing device is one of either a ground station along the communication path or the target device, and wherein performing one or more actions based on the distance between the communication satellite and the target device comprises sending the distance to the other of the target device or the ground station, respectively.

32. The method as in claim 1, wherein the communication satellite is selected from a group consisting of: a geosynchronous equatorial orbit (GEO) satellite; a medium earth orbit (MEO) satellite; and a low earth orbit (LEO) satellite.

35. The method as in claim 34, wherein compensating is based on one or more motion tracking sensors on the target device.

36. The method as in claim 1, wherein the transmitting of the initiated message is in response to detecting denial of a primary location determination system.

37. The method as in claim 1, wherein the transmitting of the initiated message is performed by the target device in response to a trigger communicated from a primary device local to the target device.

39. The method as in claim 38, wherein the accuracy of the location of the communication satellite is determined by a ground station along the communication path and shared with the target device for use by the target device.